In conventional optical imaging systems, a resolution of images generated by the system is ordinarily limited primarily by a size of the aperture of the system. In general, the greater the size of the system aperture, the greater the resolution of images generated by the system. Achievable resolutions of an imaging system are therefore generally determined by size, weight, and power (SWAP) considerations for a given application, as increasing the system aperture size typically requires increasing size and weight of optical components of the system. Conventional optical imaging systems use circular imaging objectives with circular apertures in order to generate images having substantially uniform spatial resolution in every direction.